1. Fractions and Decimals
Lesson 5-5 (Glencoe)
Unit 1: Comparing and Ordering Positive Rational Numbers and Integers (Cscope)

2. TEKS 7.1 B
7.1 Students represent and use numbers in a variety of equivalent forms. (B) convert between fractions, decimals. Whole numbers, and percents mentally, on paper, or with a calculator

3. Writing Fractions as Decimals
The table shows the heights of the ten tallest buildings in Dallas.
Building
Height (ft)
Bank of America Plaza
921
Renaissance Tower
886
Bank One Center
787
JP Morgan Chase Tower
738
Fountain Place
721
Trammell Crow Center
686
1700 Pacific Avenue
655
Thanksgiving Tower
645
Energy Plaza
629
Elm Place
625
What fraction of he buildings are between 600 and 800 feet tall?
Express this fraction using words and then a decimal. 8 10

4. Express this fraction using words and then a decimal. 8 10
When the denominator of a fraction is a power of 10, use place value to write the fraction as a decimal
Words
eight tenths
Model
Fraction
8/10
Decimal
0.8

5. Now you try…
Building
Height (ft)
Bank of America Plaza
921
Renaissance Tower
886
Bank One Center
787
JP Morgan Chase Tower
738
Fountain Place
721
Trammell Crow Center
686
1700 Pacific Avenue
655
Thanksgiving Tower
645
Energy Plaza
629
Elm Place
625
What fraction of buildings are between 710 and 850 feet tall?
Express this fraction using words and then as a decimal.

6. What have we learned so far?
When a denominator of a fraction is a factor of 10, 100, 1000 you can use mental math.
Name some factors of: 10
100
1000

7. Examples of using Mental Math:
Write each fraction or mixed number as a decimal.
THINK So, 7 7 20 35
100
x 5
= 0.35 20 20
5 ¾
Think of the mixed number as a sum = 5 + ¾
You know ¾ = 0.75 so, =
Add mentally = 5.75
So, 5 ¾ = 5.75

8. Check Your Progress
3/10
3/25
6 ½
= 0.3
= 0.12
= 6.5

9. Any fraction can be written as a decimal by dividing its numerator by its denominator. Division ends when the remainder is zero.
Write 3/8 as a decimal.
Denominator outside
Numerator inside the division icon . 3 7 5 8 3
-24 6
- 5 6 4
- 4 0
Division ends when the remainder is zero

10. Check Your Progress
7/8
2 1/8
2/3
8 1/3
= 0.875
= 2.125
= 0.66
= 8.33

11. Putting it to Practice Glencoe page 247
1-11 (odd and check your answers on pg. 296)
(all)
46 (if you cannot figure out the answer, write down your thoughts)